1. Field of the Invention
The invention relates to a roll sheet image forming apparatus configured to feed and guide a continuous sheet wound in a roll shape even when the continuous sheet has a large roll diameter incapable of being accommodated in a preset mounting unit.
2. Description of the Related Art
In an image forming apparatus such as a printer, a copier, a facsimile and the like, an inkjet type configured to discharge ink to form an image on a medium to be printed and an electrophotographic type configured to form an image on a medium to be printed by using toner have been generally used. There is an image forming apparatus configured to selectively use both a cut sheet and a continuous sheet wound in a roll shape (hereinafter, also referred to as ‘roll sheet’), as the medium to be printed.
For example, JP-A-H10-198096 discloses a copier 10 in which a roll sheet unit 70 configured to accommodate therein a roll sheet 72 is provided to be displaceable between a pulled-out state and an incorporated state, the roll sheet 72 accommodated in the roll sheet unit 70 is precut to a predetermined size by a cutter 100 provided in the roll sheet unit 70 and is fed to an image forming unit in the apparatus and an image is formed thereon.
The image forming apparatus configured to form an image is widely available in the market. Since the image forming apparatus available in the market is mass-produced, the cost thereof is decreasing.
For this reason, it may be possible to cost down a roll sheet image forming apparatus capable of forming an image on a roll sheet and the like by adopting a configuration of the image forming apparatus for the image forming unit configured to form an image on the roll sheet and the like.
For example, JP-A-2014-052433 suggests a label printer 1 in which a printer main body 10 is placed on a mount unit 82 having an unwinder 84 arranged therein, which is a roll sheet unwinding device, a roll sheet 200 is unwound by the unwinder 84, an image is formed thereon by an upper image forming unit (printer main body 10), the roll sheet is wound at one time by a rewinder 86, which is a winding device, and a large amount of labels or seals can be continuously printed.
In the meantime, for example, JP-A-2012-000815 discloses a configuration of, when a remaining amount of a continuous recording medium such as roll sheet is insufficient, splicing a new continuous recording medium to the continuous recording medium being used until then by a splicing tape and the like for a replacement operation of the continuous recording medium, and control of a splicing part.
However, when a roll sheet accommodation area is configured in the apparatus, such as the lower part of the printing unit, like the image forming apparatus using the roll sheet disclosed in JP-A-H10-198096 and JP-A-2014-052433, a maximum outer diameter of the useable roll sheet is physically determined depending on an apparatus main body. That is, since the entire apparatus is designed to normally reduce an equipment area and an overall height of the apparatus, the roll sheet accommodation space is naturally determined by a size of the apparatus main body. For example, in JP-A-H10-198096, a diameter of the roll sheet 72 corresponds to a size (height) of the roll sheet unit 70, and in JP-A-2014-052433, a diameter of the unwinder 84 corresponds to a size (height) of the mount unit 82.
However, a user may want to print (to feed a large capacity of continuous sheet) a roll sheet having a large diameter incapable of being accommodated in the apparatus. In this case, it is considered to configure a feeding unit (external feeding unit) of a roll sheet at an outside of the apparatus, to add an opening on a side surface of the apparatus and to guide a front end of the roll sheet to a sheet setting position. However, the structure is complicated and an operation thereof is troublesome. In particular, when an operation space in the vicinity of the sheet setting position is narrow or when the roll sheet is set and the front end of the sheet is manually guided to a predetermined position, the operation is difficult.
Regarding the above technical problems, JP-A-H10-198096 and JP-A-2014-052433 do not disclose favorable measures, i.e., do not suggest the configuration of feeding the continuous sheet from the outside and do not recognize the problems.
In the meantime, JP-A-2012-000815 discloses a technology of splicing the continuous recording media each other. However, as described above, when the operation space of the feeding guide unit is narrow, it is difficult to perform the splicing operation. Also, it does not disclose the configuration of feeding the continuous sheet from the outside.